Target indicator



-Nov. 1, 1949. A. c. STEPHENS TARGET INDICATOR Filed July 10, 1946 I INVENTQR LLEN 6. STEPHENS BY I 1/ q i A ATTORNEYS Patented Nov. 1, 1949 UNITED STATES OFFICE 1 This invention is directed to a target-indicating device; in particular, the invention relates to the indicating of a target for an X-ray machine. X-rays are, of course, invisible to the human eye. When an X-ray machine is being directed toward a target, it must be lined up with the target with considerable accuracy if the X-rays are to cause the best pictures upon the photographic plate. When X-rays are being taken of the human body, it is somewhat difiicult to line up the machine, patient, grid and film for any shot. In taking angle shots of the body, it is very diflicult to determine by guess where the center line of the X-ray beam will, when extended, enter the body. Current practice is to line up the axis of the focusing cone of the X-ray machine as well as possible by sight and trust to the large size of the photgraphic plate to take care of any lack of accuracy in properly lining up the machine.

It isan object of this invention to produce a simple device which may be applied to X-ray ma- 3 Claims. (01. 250-64) chines of various types in order that they may be quickly and accurately lined up for the taking of X-ray photographs or fluoroscopy, particularly when said photographs are being taken at an angle. A further object of the invention is to produce an X-ray spotting device which is rugged and durable in construction. A further object is to provide a means whereby the X-ray technique will be simplified so that continued and repeated photographs can be consistently obtained.

Generally these objects of the invention are obtained by constructing a conically-shaped and stepped head which is adapted to fit a variety of sizes of X-ray focusing cones and to be selfcentering in each of said cones. Inside this head is provided a light of suitable power, and attached to one end of the head is a hollow tube having a small aperture in the outer end thereof so that light emitted from the bulb passes through the tube and outwardly therefrom as a beam of light.

The means by which the objects of the invenand composed of a series of angular steps. The diameters of these steps are such as to conform closely with the inside diameters of the focusing cones for different X-ray machines. It is noted at this point that various types of X-ray machines have focusing cones of varying sizes, and the terraced rings of the head A are such that the head, when inserted in a, cone, such as is illustrated diagrammatically at C, will automatic'ally center itself in the cone.

- The head may be constructed of wood, plastic, metal, or any other suitable material. The upper apex of the cone is provided with a hole in which is fitted a socket 2 extended at its lower end into a reflector 4, and having at its upper end brackets 6 adapted to be secured to the upper end of the head A by screws 8. A light bulb I0 is mounted in the'socket. The base of head A is closed by a plate I4 removably secured to head A so that access may be had to the light bulb.

The wall of the head A has a bore l2 extending from the lower edge thereof to the upper edge, and the bottom plate I4 of the head A has an opening therein to receive a switch [6. An electric light cable I8, provided with a wall plug fixture 20, is passed through bore I2 and connected in series with switch it. The end of one wire 26 of cable [8 is electrically joined to light bulb I0 at 24 and the end 22 of the second wire to the socket 2 through screw 8 in a conventional manner to complete the electrical circuit for the bulb.

. Ventilating holes 28 are drilled through the head A to permit escape of the heat generated by the bulb. Tube B is threadedly or otherwise secured to bottom plate l4 and is mounted coaxially with head A. The bottom end of tube B is provided with an aperture plate 30 so that only a small beam of light is emitted from the tube.

In practice, assuming that an X-ray is to be taken of a hip of a person, after the patient has been placed on the table, the X-ray focusing cone is brought to its approximate angle and then, the plug 20 having been connected to a source of electrical current, the head A is manually inserted into the X-ray cone and automatically centers itself with respect thereto. The switch I6, shown as of the push-button type, is then pressed, il-

luminating the bulb, the light therefrom passing cone and head until the spot of light shines upon the exact portion of the body into which he wishes the X-rays to enter in order to obtainv the desired X-ray picture. The spotter is then removed from the cone, the latter remaining in place in order to focus the X-ray beams during the taking of, the desired shot.

It has been ascertained that this device can be very quickly used to correctly align the film, grid, patient and X-ray focusing cone. The spotter can be held manually in place upon a focusing cone by grasping tube B in the fingers of the hand while the thumb-of the same hand can press the switch l6. The operators other'hand is then free to be used in directing the focusing cone. Other advantages of the device lie in the fact that the time for focusing the X-ray machine is materially reduced while more accurate pictures are obtained. A further advantage lies in the: fact that, because of the increased accuracy of taking pictures, a smaller size photographic plate can be used with the consequent saving of expense as compared with the old practice of merely shooting for the generaf picture area and using a large plate.

A modified form of the invention is illustrated in Figure 3 in which the head A and tube B are essentially the same as illustrated in Figures 1 and 2. However, the bulb l is placed in a light box D secured to the underside of the head, Base plate 14 is apertured at 60. A. visible light reflector 4'2, composed of any material transparent to X-rays, such as aluminum, is inserted across the upper end ofjthe inside of head A and so angled with respect to the axis of the head that light emitted from bulb f0" strikes the reflector and passes through tube B coaxial with head A. Bulb I0" is connected by means of cable l8" and switch It" to plug 20".

This head is used essentially the same way as the device of Figure I, the head A being. inserted into a focusing cone and. automatically centerlng itself with. respect thereto. When bulb I0 is illuminated, the light reflected by reflector 42 provides a spot of light upon the patient which represents the center of the area whichv will be X-rayed. The device of Figure 3 has the following advantage in that, inasmuch as the aluminum reflector is transparent to X-rays, the device can be permanently securedin place upon a focusing cone by means of any suitable bracket.

It is also apparent that the device of Figures 1 and 2 can be attached by suitable brackets to the head of an X-ray machine so that it can be swung into and out of position desired, although normally it is preferred that it be handled manually. The spotter device can also be used with the so-called dumbbell X-ray heads, which do not use a focusing cone, by providing an adapter in the form of a focusing cone for such dumbbell X-ray heads.

Having now described the means by which the objects of my invention are obtained,

I claim:

1. In an X-ray target indicating device which includes means for projecting a beam of visible lightin the direction of the path of X-rays' emitted from an X-ray tube, the improvement comprising a head member having a plurality of surfaces extending at right angles to the axis of said beam of" light, said surfaces being spaced from eachother longitudinally of said axis, whereby said surfaces are adapted to conform respectively'to thediameters of the bases of different X-ray focusing cones.

2. In an X-ray targetindicating device which includes means for projecting a beam of. visibl'e light in the direction of the path of the. X-rays emittedv from an X-ray tube, the improvementcomprising a terraced housing adapted to be manually positioned selectively on the bases ofa. plurality of X-ray cones, said terraced housing including a plurality of planesurfaces each of which is adapted to bear against a selected cone base, and means for centering, said light beam with respect to the longitudinal axis of said housing so that said beam of light is projected along the axis of said. cone- '3. In an X-ray target indicating device as. in. claim 2, theimprovement further comprising an elongated tube coaxially secured to said housing and extending therefrom, whereby saidv light beam isprojected through said. elongated tube.

ALLEN C. STEPHENS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 994,441 Burke June 6, 1911 1,976,179 Mannl Oct. 9, 1934 2,I8 l',620 Haupt Nov. 28, 1939 2,204,465 Baier June 11,- 1946 FOREIGN PATENTS Number Country Date 530,010 Austria Nov. 1, I911 

